1,466 research outputs found
Assembling defenses against therapy-resistant leukemic stem cells: Bcl6 joins the ranks
The resistance of leukemic stem cells in response to targeted therapies such as tyrosine kinase inhibitors (TKIs) relies on the cooperative activity of multiple signaling pathways and molecules, including TGFβ, AKT, and FOXO transcription factors (TFs). B cell lymphoma 6 (BCL6) is a transcriptional repressor whose translocation or mutation is associated with diffuse large BCL. New data now show that BCL6 is critical for the maintenance of leukemias driven by the BCR-ABL translocation (Philadelphia chromosome), suggesting that BCL6 is a novel, targetable member of the complex signaling pathways critical for leukemic stem cell survival
Izdvajanje i identifikacija mikroflore iz kravljeg kolostruma tradicionalnim i molekularnim metodama
Colostrum is the first milk produced by the mammary gland during the early postpartum period. In addition to nutrients, antimicrobial and growth factors, bovine colostrum contains valuable microflora, including members of the genera Lactobacillus and Bifidobacterium, which have been used widely in probiotic food. The aim of this work is to identify and quantify the microflora of colostrum samples from two Holstein dairy cows on the first three postpartum days through culture-dependent 16S rRNA gene sequencing and length heterogeneity polymerase chain reaction (LH-PCR) techniques, using an adapted method to extract the total DNA. Twenty-nine strains isolated in synthetic media were identified by their 16S rRNA gene sequences, revealing two potential probiotic strains (Lactobacillus casei and Bifidobacterium pseudolongum). Colostrum samples were subjected to LH-PCR analysis to obtain fingerprint profiles of the microflora. Lactobacillus casei was the main species present in the samples. The probiotic potential of these bacteria for use in fermented and functional foods remains to be evaluated.Kolostrum je prvo mlijeko, koje proizvodi mliječna žlijezda tijekom ranog postpartalnog razdoblja. Osim što sadrži hranjiva, antimikrobne tvari i hormone rasta, kravlji kolostrum sadržava dragocjenu mikrofloru, uključujući sojeve rodova Lactobacillus i Bifidobacterium što se koriste u proizvodnji probiotičke hrane. Svrha je ovoga rada bila identificirati i kvantificirati mikrofloru u uzorcima kolostruma dvaju Holstein mlječnih krava, uzetih tijekom prva tri dana postpartalnog razdoblja. Mikroorganizmi su određeni sekvenciranjem 16S rRNK gena i LH-PCR metodom kojom se ekstrahira ukupna DNK. U sintetičkoj je podlozi izolirano dvadeset i devet sojeva, identificiranih pomoću sekvencija 16S rRNK gena, te su izdvojena dva potencijalno probiotička soja (Lactobacillus casei i Bifidobacterium pseudolongum). Uzorci su kolostruma analizirani LH-PCR metodom kako bi se utvrdio DNK profil mikroflore, te je utvrđeno da u uzorcima prevladava vrsta Lactobacillus casei. Probiotička svojstva ove bakterije za proizvodnju fermentiranih i probiotičkih proizvoda tek treba istražiti
A 5-year retrospective study of demographic, anamnestic, and clinical factors related to psychiatric hospitalizations of adolescent patients
Background: Psychiatric emergencies of children and adolescents have greatly increased during the last years, but this phenomenon has not been studied in detail. The aim of this study was to analyze the correlation between acute psychiatric hospitalizations of adolescents and selected variables to highlight risk factors for psychiatric emergencies.
Methods: This retrospective research was conducted in the acute psychiatric public ward, Service of Psychiatric Diagnosis and Treatment (SPDT), and in the residential facility for adolescents, “The Medlar”, located in Modena. The sample was constituted by all adolescent patients (n=101, age range 14–18) who had acute hospitalizations (n=140) in SPDT and had been successively transferred to “The Medlar” (n=83), from February 2, 2010 to January 31, 2015. From clinical charts, we extracted demographic and anamnestic characteristics of patients and clinical variables related to hospitalizations. Data were statistically analyzed.
Results: Sixty-one percent of our patients lived with one divorced parent, with adoptive or immigrant family, or in institutions; 51% had experienced stressful events during childhood; 81% had a normal intellective level, but only 6% presented regular school performance. Parental psychiatric illness was negatively related, in a statistically significantly way, with onset age of adolescent mental disorders (coefficient -2.28, 95% confidence interval [CI]: -3.53 to 1.01, P<0.001, single linear regression; odds ratio: 4.39, 95% CI: 1.43–13.47, P<0.010, single logistic regression). The most frequent reasons for admission were aggressive behavior in males and suicide risk in females (P=0.002). The most frequent psychiatric diagnosis at SPDT discharge was “conduct disorder”, more frequent in males, followed by “adjustment disorder”, more frequent in females (P=0.001). In SPDT, the adolescent hospitalizations progressively increased fivefold at the end of the observation period.
Conclusion: Our results overlap the worldwide trend of increasing adolescent psychiatric hospitalizations, suggest risk factors like parental psychiatric illness and early life stressful events, and highlight the different prevalence of aggressiveness and suicide in males and females
A 64-Channel 965-μW Neural Recording SoC with UWB Wireless Transmission in 130-nm CMOS
This brief presents a 64-channel neural recording system-on-chip (SoC) with a 20-Mb/s wireless telemetry. Each channel of the analog front end consists of a low-noise bandpass amplifier, featuring a noise efficiency factor of 3.11 with an input-referred noise of 5.6 μVrms in a 0.001- to 10-kHz band and a 31.25-kSps 6-fJ/conversion-step 10-bit SAR analog-to-digital converter. The recorded signals are multiplexed in the digital domain and transmitted via an 11.7% efficiency pulse-position modulation ultrawideband transmitter, reaching a transmission range in excess of 7.5 m. The chip has been fabricated in a 130-nm CMOS process, measures 25 mm2, and dissipates 965 μW from a 0.5-V supply. This SoC features the lowest power per channel (15 μW) and the lowest energy per bit (48.2 pJ) among state-of-the-art wireless neural recording systems with a number of channels larger than 32. The proposed circuit is able to transmit the raw neural signal in a large bandwidth (up to 10 kHz) without performing any data compression or losing vital information, such as local field potentials
Elucidating the role of the tumor suppressor Protein Phoshatase 2A in Chronic Myeloid Leukemia.
Protein phosphatase-2A (PP2A) is one of the major cellular serine-threonine
phosphatases and is involved in the regulation of cell homeostasis through the
negative regulation of signaling pathways initiated by protein kinases. As several
cancers are characterized by the aberrant activity of oncogenic kinases, it was not
surprising that a phosphatase like PP2A has progressively been considered as a
potential tumor suppressor. Indeed, multiple solid tumors (e.g. melanomas,
colorectal carcinomas, lung and breast cancers) present with genetic and/ or
functional inactivation of different PP2A subunits and, therefore, loss of PP2A
phosphatase activity towards certain substrates. Likewise, impaired PP2A
phosphatase activity has been linked to B-cell chronic lymphocytic leukemia,
Philadelphia-chromosome positive acute lymphoblastic leukemia and blast crisis
chronic myeloid leukemia (CML). In CML the deregulated tyrosine kinase activity of
p210-BCR/ABL oncoproteins is sufficient to induce and sustain the leukemic
phenotype, and contributes to disease progression. Imatinib mesylate, a BCR/ABL
kinase inhibitor, is effective in most of chronic phase CML patients. However, a
significant percentage of CML patients develop resistance to imatinib and/or still
progresses to blast crisis, a disease stage that is often refractory to imatinib
therapy. Furthermore, there is compelling evidence indicating that the CML
leukemia stem cell is also resistant to imatinib. We have recently reported that the
phosphatase activity of PP2A is markedly inhibited in blast crisis and, to a lesser
extent, chronic phase CML patient cells and that pharmacologic re-activation of
PP2A phosphatase activity by activating drugs such as Forskolin and FTY720 led
to growth suppression, enhanced apoptosis impaired clonogenic potential and
decreased in vivo leukemogenesis of imatinib-sensitive and
-resistant CML-BC and CML-CP patient. Furthermore we have evidence that PP2A
inactivation is an event that occurs also at the level of the leukemic stem cell and
that PP2A re-activation hampers the survival and self-renewal of CML stem cells
and possibly overcome the resistance of CML quiescent stem cells to tyrosine
kinase inhibitor monotherapy. Thus, inducing PP2A phosphatase activity has the
potential to eradicate CML by efficiently targeting both leukemic stem and
progenitor cells regardless of their degree of sensitivity to kinase. Therefore, the
combination of PP2A phosphatase-activating and BCR/ABL kinase-inhibiting drugs
may represent a powerful therapeutic strategy for CML patients
Multiscale mathematical models for simulation and scale-up of green processes in the perspective of industrial sustainability
The present work presents research studies aimed at developing tools useful to design
engineering solutions moving in the direction of industrial sustainability. The investigations
hereinafter discussed regard an extraction process of active compounds \u2013 polyphenols \u2013 from
agro-food industry wastes (olive and grape pomaces) and a biorefinery exploiting waste
frying oil, solid organic wastes and algal biomass to produce biofuels. In particular, for the
former topic, a procedure aimed at the evaluation of the technological feasibility at pilot scale
of said process is discussed. The proposed approach takes into consideration the extended
kinetic route coupled with mathematical simulation. Detailed physically-based dynamic
mathematical models, taking into account mass and energy balance equations, are adopted
to describe both the lab-scale and the pilot-scale reactors. Chemical physical parameters
appearing in the models are estimated from the experimental data at lab-scale or are partially
taken from literature. Different heating systems are designed for the pilot scale reactor and
their performance is tested by simulation. Characteristic times are evaluated also during
start-ups and different control loops are analyzed in order to set-up the best process and
operating variables. Average yields in polyphenols are finally evaluated for both the batch
and the continuous operated pilot reactor, by considering feed variability and fluctuations of
process parameters.
For what concerns the biorefinery, special attention was devoted to the modeling of the
airlift reactor, its most delicate and complex component. In fact, to optimize this interesting
microalgae cultivation system, a precise description of the moving interfaces formed by the
liquid and gas phase is critical. In this study, coupled front capturing methods (standard and
conservative level set methods) and finite difference method are used to simulate gas bubbles
dynamics in a pilot-scale external loop air-lift photobioreactor in which microalgae are used
to capture CO2 from flue gas and to treat wastewater. Numerical simulations are carried out
on rectangular domains representing different sections of the vertical axis of the riser. The
data employed was either acquired from previous experimental campaigns carried out in the
airlift reactor or found in the literature. The rise, shape dynamics and coalescence process of
the bubbles of flue gas are studied.
Moreover, for each analyzed applications, a procedure based on Buckingham \u3c0-theorem
to perform a rigorous scale-up is proposed. In this way, scale-invariant dimensionless
groups describing and summarizing the considered processes could be identified. For the
research focused on the scale-up of photobioreactors used to cultivate Chlorella Vulgaris,
an experimental campaign at three levels was designed and carried out to evaluate the
characteristic dimensionless numbers individuated by the theoretical formulation. Since
scale-up regards both geometrical dimensions and type of reactor, passing from lab-scale
stirred tanks to pilot scale tubular and airlift, particular attention was devoted to define
characteristic lengths inside the dimensionless numbers
Protein phosphatase 2A as a therapeutic target in acute myeloid leukemia
Acute myeloid leukemia (AML) is a heterogeneous malignant disorder of hematopoietic progenitor cells in which several genetic and epigenetic aberrations have been described. Despite progressive advances in our understanding of the molecular biology of this disease, the outcome for most patients is poor. It is therefore necessary to develop more effective treatment strategies. Genetic aberrations affecting kinases have been widely studied in AML; however, the role of phosphatases remains underexplored. Inactivation of the tumor suppressor protein phosphatase 2A (PP2A) is frequent in AML patients, making it a promising target for therapy. There are several PP2A inactivating mechanisms reported in this disease. Deregulation or specific post-translational modifications of PP2A subunits have been identified as a cause of PP2A malfunction, which lead to deregulation of proliferation or apoptosis pathways, depending on the subunit affected. Likewise, overexpression of either SET or CIP2A, endogenous inhibitors of PP2A, is a recurrent event in AML that impairs PP2A activity, contributing to leukemogenesis progression. Interestingly, the anticancer activity of several PP2A-activating drugs (PADs) depends on interaction/sequestration of SET. Preclinical studies show that pharmacological restoration of PP2A activity by PADs effectively antagonizes leukemogenesis, and that these drugs have synergistic cytotoxic effects with conventional chemotherapy and kinase inhibitors, opening new possibilities for personalized treatment in AML patients, especially in cases with SET-dependent inactivation of PP2A. Here, we review the role of PP2A as a druggable tumor suppressor in AML
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